1 files changed, 356 insertions, 70 deletions

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index b2a616287638..4cf74f173c78 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -34,6 +34,7 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h>
+#include <linux/pnp.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
 #include <acpi/video.h>
@@ -49,6 +50,12 @@ static void acpi_video_parse_cmdline(void)
 		acpi_backlight_cmdline = acpi_backlight_video;
 	if (!strcmp("native", acpi_video_backlight_string))
 		acpi_backlight_cmdline = acpi_backlight_native;
+	if (!strcmp("nvidia_wmi_ec", acpi_video_backlight_string))
+		acpi_backlight_cmdline = acpi_backlight_nvidia_wmi_ec;
+	if (!strcmp("apple_gmux", acpi_video_backlight_string))
+		acpi_backlight_cmdline = acpi_backlight_apple_gmux;
+	if (!strcmp("dell_uart", acpi_video_backlight_string))
+		acpi_backlight_cmdline = acpi_backlight_dell_uart;
 	if (!strcmp("none", acpi_video_backlight_string))
 		acpi_backlight_cmdline = acpi_backlight_none;
 }
@@ -125,13 +132,21 @@ static int video_detect_force_native(const struct dmi_system_id *d)
 	return 0;
 }
 
-static int video_detect_force_none(const struct dmi_system_id *d)
+static int video_detect_portege_r100(const struct dmi_system_id *d)
 {
-	acpi_backlight_dmi = acpi_backlight_none;
+	struct pci_dev *dev;
+	/* Search for Trident CyberBlade XP4m32 to confirm Portégé R100 */
+	dev = pci_get_device(PCI_VENDOR_ID_TRIDENT, 0x2100, NULL);
+	if (dev)
+		acpi_backlight_dmi = acpi_backlight_vendor;
 	return 0;
 }
 
 static const struct dmi_system_id video_detect_dmi_table[] = {
+	/*
+	 * Models which should use the vendor backlight interface,
+	 * because of broken ACPI video backlight control.
+	 */
 	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1128309 */
 	 .callback = video_detect_force_vendor,
@@ -166,6 +181,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		},
 	},
 	{
+	 /* https://bugs.launchpad.net/bugs/1000146 */
 	 .callback = video_detect_force_vendor,
 	 /* Asus X101CH */
 	 .matches = {
@@ -190,6 +206,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		},
 	},
 	{
+	 /* https://bugs.launchpad.net/bugs/1000146 */
 	 .callback = video_detect_force_vendor,
 	 /* Asus 1015CX */
 	 .matches = {
@@ -199,14 +216,6 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_vendor,
-	 /* GIGABYTE GB-BXBT-2807 */
-	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "GB-BXBT-2807"),
-		},
-	},
-	{
-	 .callback = video_detect_force_vendor,
 	 /* Samsung N150/N210/N220 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
@@ -232,20 +241,25 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_BOARD_NAME, "NC210/NC110"),
 		},
 	},
+
+	/*
+	 * Models which should use the vendor backlight interface,
+	 * because of broken native backlight control.
+	 */
 	{
 	 .callback = video_detect_force_vendor,
-	 /* Sony VPCEH3U1E */
+	 /* Sony Vaio PCG-FRV35 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "PCG-FRV35"),
 		},
 	},
 	{
 	 .callback = video_detect_force_vendor,
-	 /* Xiaomi Mi Pad 2 */
+	 /* Panasonic Toughbook CF-18 */
 	 .matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Xiaomi Inc"),
-			DMI_MATCH(DMI_PRODUCT_NAME, "Mipad2"),
+		DMI_MATCH(DMI_SYS_VENDOR, "Matsushita Electric Industrial"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "CF-18"),
 		},
 	},
 
@@ -269,6 +283,45 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 
 	/*
+	 * Toshiba Portégé R100 has working both acpi_video and toshiba_acpi
+	 * vendor driver. But none of them gets activated as it has a VGA with
+	 * no kernel driver (Trident CyberBlade XP4m32).
+	 * The DMI strings are generic so check for the VGA chip in callback.
+	 */
+	{
+	 .callback = video_detect_portege_r100,
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Portable PC"),
+		DMI_MATCH(DMI_PRODUCT_VERSION, "Version 1.0"),
+		DMI_MATCH(DMI_BOARD_NAME, "Portable PC")
+		},
+	},
+
+	/*
+	 * Models which need acpi_video backlight control where the GPU drivers
+	 * do not call acpi_video_register_backlight() because no internal panel
+	 * is detected. Typically these are all-in-ones (monitors with builtin
+	 * PC) where the panel connection shows up as regular DP instead of eDP.
+	 */
+	{
+	 .callback = video_detect_force_video,
+	 /* Apple iMac14,1 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "iMac14,1"),
+		},
+	},
+	{
+	 .callback = video_detect_force_video,
+	 /* Apple iMac14,2 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "iMac14,2"),
+		},
+	},
+
+	/*
 	 * These models have a working acpi_video backlight control, and using
 	 * native backlight causes a regression where backlight does not work
 	 * when userspace is not handling brightness key events. Disable
@@ -400,8 +453,8 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
 		},
 	},
-	/* https://bugs.launchpad.net/bugs/1894667 */
 	{
+	 /* https://bugs.launchpad.net/bugs/1894667 */
 	 .callback = video_detect_force_video,
 	 /* HP 635 Notebook */
 	 .matches = {
@@ -421,12 +474,21 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		},
 	},
 	{
+	 /* https://bugzilla.suse.com/show_bug.cgi?id=1208724 */
+	 .callback = video_detect_force_native,
+	 /* Lenovo Ideapad Z470 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_VERSION, "IdeaPad Z470"),
+		},
+	},
+	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
 	 .callback = video_detect_force_native,
 	 /* Lenovo Ideapad Z570 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
+		DMI_MATCH(DMI_PRODUCT_VERSION, "Ideapad Z570"),
 		},
 	},
 	{
@@ -446,6 +508,80 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		},
 	},
 	{
+	 .callback = video_detect_force_native,
+	 /* Lenovo Slim 7 16ARH7 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "82UX"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Lenovo ThinkPad X131e (3371 AMD version) */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "3371"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Apple iMac11,3 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "iMac11,3"),
+		},
+	},
+	{
+	 /* https://gitlab.freedesktop.org/drm/amd/-/issues/1838 */
+	 .callback = video_detect_force_native,
+	 /* Apple iMac12,1 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "iMac12,1"),
+		},
+	},
+	{
+	 /* https://gitlab.freedesktop.org/drm/amd/-/issues/2753 */
+	 .callback = video_detect_force_native,
+	 /* Apple iMac12,2 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "iMac12,2"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Apple MacBook Air 7,2 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir7,2"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Apple MacBook Air 9,1 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir9,1"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Apple MacBook Pro 9,2 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro9,2"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Apple MacBook Pro 11,2 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro11,2"),
+		},
+	},
+	{
 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
 	 .callback = video_detect_force_native,
 	 /* Apple MacBook Pro 12,1 */
@@ -456,6 +592,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
+	 /* Apple MacBook Pro 16,2 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,2"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
 	 /* Dell Inspiron N4010 */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
@@ -489,6 +633,30 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
+	 /* Dell Studio 1569 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1569"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Acer Aspire 3830TG */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 3830TG"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Acer Aspire 4810T */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 4810T"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
 	 /* Acer Aspire 5738z */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
@@ -576,6 +744,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
+	 /* Asus U46E */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "U46E"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
 	 /* Asus UX303UB */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
@@ -584,6 +760,23 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 	{
 	 .callback = video_detect_force_native,
+	 /* HP EliteBook 8460p */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8460p"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* HP Pavilion g6-1d80nr / B4U19UA */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion g6 Notebook PC"),
+		DMI_MATCH(DMI_PRODUCT_SKU, "B4U19UA"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
 	 /* Samsung N150P */
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
@@ -609,6 +802,23 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_BOARD_NAME, "N250P"),
 		},
 	},
+	{
+	 /* https://bugzilla.kernel.org/show_bug.cgi?id=202401 */
+	 .callback = video_detect_force_native,
+	 /* Sony Vaio VPCEH3U1E */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
+		},
+	},
+	{
+	 .callback = video_detect_force_native,
+	 /* Sony Vaio VPCY11S1E */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VPCY11S1E"),
+		},
+	},
 
 	/*
 	 * These Toshibas have a broken acpi-video interface for brightness
@@ -646,6 +856,30 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 
 	/*
+	 * Dell AIO (All in Ones) which advertise an UART attached backlight
+	 * controller board in their ACPI tables (and may even have one), but
+	 * which need native backlight control nevertheless.
+	 */
+	{
+	 /* https://github.com/zabbly/linux/issues/26 */
+	 .callback = video_detect_force_native,
+	 /* Dell OptiPlex 5480 AIO */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 5480 AIO"),
+		},
+	},
+	{
+	 /* https://bugzilla.redhat.com/show_bug.cgi?id=2303936 */
+	 .callback = video_detect_force_native,
+	 /* Dell OptiPlex 7760 AIO */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7760 AIO"),
+		},
+	},
+
+	/*
 	 * Models which have nvidia-ec-wmi support, but should not use it.
 	 * Note this indicates a likely firmware bug on these models and should
 	 * be revisited if/when Linux gets support for dynamic mux mode.
@@ -658,25 +892,68 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_PRODUCT_NAME, "Dell G15 5515"),
 		},
 	},
+	{
+	 .callback = video_detect_force_native,
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 15 3535"),
+		},
+	},
 
 	/*
-	 * Desktops which falsely report a backlight and which our heuristics
-	 * for this do not catch.
+	 * x86 android tablets which directly control the backlight through
+	 * an external backlight controller, typically TI's LP8557.
+	 * The backlight is directly controlled by the lp855x driver on these.
+	 * This setup means that neither i915's native nor acpi_video backlight
+	 * control works. Add a "vendor" quirk to disable both. Note these
+	 * devices do not use vendor control in the typical meaning of
+	 * vendor specific SMBIOS or ACPI calls being used.
 	 */
 	{
-	 .callback = video_detect_force_none,
-	 /* Dell OptiPlex 9020M */
+	 .callback = video_detect_force_vendor,
+	 /* Lenovo Yoga Book X90F / X90L */
 	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
+		DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Intel Corporation"),
+		DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "CHERRYVIEW D1 PLATFORM"),
+		DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "YETI-11"),
+		},
+	},
+	{
+	 .callback = video_detect_force_vendor,
+	 /*
+	  * Lenovo Yoga Tablet 2 830F/L or 1050F/L (The 8" and 10"
+	  * Lenovo Yoga Tablet 2 use the same mainboard)
+	  */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Intel Corp."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VALLEYVIEW C0 PLATFORM"),
+		DMI_MATCH(DMI_BOARD_NAME, "BYT-T FFD8"),
+		/* Partial match on beginning of BIOS version */
+		DMI_MATCH(DMI_BIOS_VERSION, "BLADE_21"),
+		},
+	},
+	{
+	 .callback = video_detect_force_vendor,
+	 /* Lenovo Yoga Tab 3 Pro YT3-X90F */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Intel Corporation"),
+		DMI_MATCH(DMI_PRODUCT_VERSION, "Blade3-10A-001"),
+		},
+	},
+	{
+	 .callback = video_detect_force_vendor,
+	 /* Xiaomi Mi Pad 2 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Xiaomi Inc"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Mipad2"),
 		},
 	},
+	/* https://gitlab.freedesktop.org/drm/amd/-/issues/4512 */
 	{
-	 .callback = video_detect_force_none,
-	 /* MSI MS-7721 */
+	 .callback = video_detect_force_native,
 	 .matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
-		DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "82K8"),
 		},
 	},
 	{ },
@@ -688,13 +965,25 @@ static bool google_cros_ec_present(void)
 }
 
 /*
+ * Windows 8 and newer no longer use the ACPI video interface, so it often
+ * does not work. So on win8+ systems prefer native brightness control.
+ * Chromebooks should always prefer native backlight control.
+ */
+static bool prefer_native_over_acpi_video(void)
+{
+	return acpi_osi_is_win8() || google_cros_ec_present();
+}
+
+/*
  * Determine which type of backlight interface to use on this system,
  * First check cmdline, then dmi quirks, then do autodetect.
  */
-static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
+enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, bool *auto_detect)
 {
 	static DEFINE_MUTEX(init_mutex);
 	static bool nvidia_wmi_ec_present;
+	static bool apple_gmux_present;
+	static bool dell_uart_present;
 	static bool native_available;
 	static bool init_done;
 	static long video_caps;
@@ -708,12 +997,17 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
 				    ACPI_UINT32_MAX, find_video, NULL,
 				    &video_caps, NULL);
 		nvidia_wmi_ec_present = nvidia_wmi_ec_supported();
+		apple_gmux_present = apple_gmux_detect(NULL, NULL);
+		dell_uart_present = acpi_dev_present("DELL0501", NULL, -1);
 		init_done = true;
 	}
 	if (native)
 		native_available = true;
 	mutex_unlock(&init_mutex);
 
+	if (auto_detect)
+		*auto_detect = false;
+
 	/*
 	 * The below heuristics / detection steps are in order of descending
 	 * presedence. The commandline takes presedence over anything else.
@@ -725,58 +1019,50 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
 	if (acpi_backlight_dmi != acpi_backlight_undef)
 		return acpi_backlight_dmi;
 
+	if (auto_detect)
+		*auto_detect = true;
+
 	/* Special cases such as nvidia_wmi_ec and apple gmux. */
 	if (nvidia_wmi_ec_present)
 		return acpi_backlight_nvidia_wmi_ec;
 
-	if (apple_gmux_present())
+	if (apple_gmux_present)
 		return acpi_backlight_apple_gmux;
 
-	/* Chromebooks should always prefer native backlight control. */
-	if (google_cros_ec_present() && native_available)
-		return acpi_backlight_native;
+	if (dell_uart_present)
+		return acpi_backlight_dell_uart;
 
-	/* On systems with ACPI video use either native or ACPI video. */
-	if (video_caps & ACPI_VIDEO_BACKLIGHT) {
-		/*
-		 * Windows 8 and newer no longer use the ACPI video interface,
-		 * so it often does not work. If the ACPI tables are written
-		 * for win8 and native brightness ctl is available, use that.
-		 *
-		 * The native check deliberately is inside the if acpi-video
-		 * block on older devices without acpi-video support native
-		 * is usually not the best choice.
-		 */
-		if (acpi_osi_is_win8() && native_available)
-			return acpi_backlight_native;
-		else
-			return acpi_backlight_video;
-	}
+	/* Use ACPI video if available, except when native should be preferred. */
+	if ((video_caps & ACPI_VIDEO_BACKLIGHT) &&
+	     !(native_available && prefer_native_over_acpi_video()))
+		return acpi_backlight_video;
 
-	/* No ACPI video (old hw), use vendor specific fw methods. */
-	return acpi_backlight_vendor;
-}
-
-enum acpi_backlight_type acpi_video_get_backlight_type(void)
-{
-	return __acpi_video_get_backlight_type(false);
-}
-EXPORT_SYMBOL(acpi_video_get_backlight_type);
+	/* Use native if available */
+	if (native_available)
+		return acpi_backlight_native;
 
-bool acpi_video_backlight_use_native(void)
-{
 	/*
-	 * Call __acpi_video_get_backlight_type() to let it know that
-	 * a native backlight is available.
+	 * The vendor specific BIOS interfaces are only necessary for
+	 * laptops from before ~2008.
+	 *
+	 * For laptops from ~2008 till ~2023 this point is never reached
+	 * because on those (video_caps & ACPI_VIDEO_BACKLIGHT) above is true.
+	 *
+	 * Laptops from after ~2023 no longer support ACPI_VIDEO_BACKLIGHT,
+	 * if this point is reached on those, this likely means that
+	 * the GPU kms driver which sets native_available has not loaded yet.
+	 *
+	 * Returning acpi_backlight_vendor in this case is known to sometimes
+	 * cause a non working vendor specific /sys/class/backlight device to
+	 * get registered.
+	 *
+	 * Return acpi_backlight_none on laptops with ACPI tables written
+	 * for Windows 8 (laptops from after ~2012) to avoid this problem.
 	 */
-	__acpi_video_get_backlight_type(true);
+	if (acpi_osi_is_win8())
+		return acpi_backlight_none;
 
-	/*
-	 * For now just always return true. There is a whole bunch of laptop
-	 * models where (video_caps & ACPI_VIDEO_BACKLIGHT) is false causing
-	 * __acpi_video_get_backlight_type() to return vendor, while these
-	 * models only have a native backlight control.
-	 */
-	return true;
+	/* No ACPI video/native (old hw), use vendor specific fw methods. */
+	return acpi_backlight_vendor;
 }
-EXPORT_SYMBOL(acpi_video_backlight_use_native);
+EXPORT_SYMBOL(__acpi_video_get_backlight_type);